[N.B. I consider Don a friend, and we have in the past, continue to, and no doubt will in the future jointly represent some authors, for differing purposes.]
I have to disagree with the skepticism people attach to Don's Writing the Breakout Novel approach. You need to remember one very critical thing: He's talking about a menu of processes, not about a necessary result. As a more-obvious example from the art world, Picasso was a gifted naturalistic/realistic painter who achieved substantial mastery of those tools before shifting toward "Guernica" and the Cubism for which he is better known.
Don's actual point could be much more explicit, but it is that those who have not already demonstrated mastery of the writing equivalent of the techniques involved in painting the naturalistic/realistic form need to engage in the process of obtaining that mastery and then extending it to produce good works, not immediately jump to experimentation without ever learning the underlying principles. Just take a look at the works Don actually sells, and you'll see that his "rigidity" is the same rigidity as the art instructor imposes in the basic drawing class, or that the piano teacher imposes on the second- and third-year student. Don is merely being diplomatic — too much so, in my opinion, but we genially disagree on this — in not characterizing most unpublished (or "underpublished") writers as the equivalent of third graders taking piano lessons.
To put it another way: Writing fiction is about a great deal more than merely putting together an argument in clear prose. Alan Dershowitz and Stephen Carter are good examples; they're both unusually good writers as law professors, but their works of fiction fall far short of the standard set by their law review articles and nonfiction books.
The real problem is that most advice offered to fiction writers is actually more suited to writing five-paragraph-form essays than to writing fiction, except when placed in the box called "characterization" (when it's usually better suited for the rubbish bin, but that's another argument entirely). Don's approach is better than the "status quo," and that's enough for me to recommend it ... especially since, unlike almost all "write a novel" books, Writing the Breakout Novel lives in the real world of commercial publishing and includes substantial valuable advice on that world.